Should Explanations of Program Code Use Audio, Text, or Both? A Replication Study

Studies in educational psychology suggest that people learn better when visual learning materials are accompanied by audio explanations rather than textual ones. Research on how this modality effect applies to computing education is scarce and inconclusive. We explore whether modality of instruction affects learning from videos that use a series of example programs to explain how variables work in Python. Learners (n=186) were crowdsourced from the internet and randomized in three groups, who received explanations as audio, text, or both, respectively. We did not find significant differences between the groups in near transfer to code-tracing tasks or perceived cognitive load. The result affirms the need to further investigate instructional modalities in programming education. There are a number of theoretical, methodological, and instructional-design factors that may explain these and earlier findings; we trace out future research that could explore those factors.